Patent infringement is the unauthorized act of making,
using, selling, offering for sale, or importing a patented invention. Allowing
patent infringement to occur can have disastrous results for a patent owner as
revenues from a patented invention are siphoned away by a competitor. On the
other hand, the results may even be more disastrous if the owner sues the
competitor and the patent is successfully challenged. For example,
Hoffman-LaRoche, an international drug company, sued a smaller company,
Promega, over the use of a patent for a process for analyzing DNA. Promega
successfully defended itself by arguing that the DNA patent was invalid because
the inventors had misled patent examiners. The ruling allows anyone to use,
sell, or make the patented invention freely even though Hoffman-La Roche paid
$300 million for the patent. As you can see, enforcing patent rights can be
tricky, expensive, and sometimes risky.

Patent laws are like stop signs along the road; people are
supposed to obey them, but some do not. Often the only way to enforce patent
laws is to drag the infringer into a federal court and obtain a court order
prohibiting infringement and requiring the infringer to pay damages. In the
following sections we discuss the elements of patent litigation and the
remedies available under patent law. We also discuss alternatives to patent
litigation.